In a typical display apparatus, a read-only memory is applied for storing basic and relevant parameter information used for configuration or initialization. After a display apparatus leaves the factory and reaches a common user, the user will then have to bring the display apparatus back to the vendor for firmware updating if necessary, which is considerably inconvenient.
There are a few methods to write firmware information into a display apparatus, which include the condition when the display apparatus is still in the factory or when a sold product requires firmware updating. The following are some examples.
In the first example, a terminal that is external to the display apparatus is reserved in advance. The terminal is to be coupled to a signal line in order to receive signals of a computer that resides externally. The drawback of this method is that an extra terminal and an extra transmission line to transmit signals are required, thus increasing design complexity and cost. In addition, the computer video card Display Data Channel (DDC) which is applied for burning firmware information directly into the display apparatus, necessitates vendors to provide burning programs that must be compatible with numerous versions of computer hardware and operation systems. Due to the fact that a computer is an open platform system that requires compatibility among burning programs, computers, video cards, and display apparatuses, such prerequisites will make the development and maintenance of burning programs very difficult.
In another example, a specific device (e.g. an interface card) can be used as the connection to the display apparatus. Firmware information is directly burned into the display apparatus in this fashion such that the detachment of the microprocessor from the display apparatus is no longer necessary. However, vendors and corresponding maintenance sites will have to manufacture and maintain such burning devices.
In a third example, chassis of the display apparatus is taken apart such that the microprocessor written with firmware information can be detached from the display apparatus. A burner is used for burning updated firmware information into the microprocessor, and the microprocessor is then remounted back into the display apparatus. This is extremely inconvenient for general users, for they will have to acquire the updated firmware information beforehand, despite the fact that they do not generally have any burning devices for the burning process. Moreover, the detachment or installation of the display apparatus and the microprocessor as described above may cause unpredictable damages or hidden risks. It is believed that all methods aforementioned may cause inconvenience and a waste of time and cost.
Consequently, a novel circuit and a method for updating firmware of a display apparatus are necessary to manage problems described above. The instant invention to be proposed will not only solve compatibility problems during computer updating, but also reduce any extra cost, i.e. by avoiding the use of burners or specific devices. In addition, detaching the microprocessor from the display apparatus will no longer be necessary, which thereby saves time and effort.